Blue belt 1 stripe reflection

So I think at this point in my Brazilian jiujitsu life, I've come to realize something about where I am as a 1 stripe blue belt. For the longest time, I've always relied on the same basic moves to get past guards or to sweep from under half guard (aka toriano(spelling?) pass and underhook to take the back). These used to be my bread and butter, especially against high white belts and even some lower level blue belts. They would never fight for the underhook, or if they did give it up, they would never counter it with a whizzer or change their base. Its at the point where I can now probably win or have an advantage over a 85% of the white belts out there, win or have an advantage against 25% of the blue belts, be about even for 50% of the other blue belts, and get COMPLETELY dominated by the other 25% of the blue belts. I think its at a point where I need to vary my game, to focus on a position and really learn it to be able to handle all situations. This includes facing a white belt but also against more advanced blue belts. I think I've learned that the point isn't to do the same thing if its not working, but to learn now moves. I'm currently in a situation where I am trying to learn how to be more effective in my half guard. People have mentioned that I get the underhook and that I tend to get on my hips pretty well, so what am I doing wrong? Some people say that I shouldn't just sit there, since I apparently don't move enough. I should focus on pushing them in one direction or another, perhaps shrugging them upwards while flaring my shoulder, or to shrimp under them and push on their hip, or even to push against them and shrimp away. These are pretty basic things I should be trying to do, and if I force them off their base enough, I might be able to rely on the sweeps that I've been doing before (underhook, friendship sweep, or go to guard).